A Shadowhunter's Proposal
by Ketchupwings
Summary: For Simon and Izzy, it was meant to be nothing more than a nighttime stroll. But for Shadowhunters, nothing is that simple...just a short two-chapter story!
1. Chapter 1

**New York, 2012**

Two years.

Two years since graduating from the Academy in Idris, and Simon found he still wasn't used to the physical grace that came with being a Shadowhunter. It wasn't just the angelic runes his skin could now bear. From the moment he'd drunk from the Mortal Cup, angel blood had sung in his veins, filling him with a newfound nimbleness and seemingly boundless energy. With his memory intact, he could now remember his months as a vampire, the strength he'd had – and still, it couldn't beat being Nephilim. Being one of Raziel's children was like having the body of a superhero.

Said body served him well in fighting demons, and in other, more personal areas of his life.

Isabelle giggled breathlessly as she lay back, tracing the _parabatai_ rune on Simon's bare chest, over his heart. "Stamina runes put to good use, I'd say."

"I'd say so too," Simon agreed breathlessly.

"So, what now, Lord Montgomery?"

Simon stretched lazily and put an arm around Izzy, pulling her to his side. They were both covered in perspiration, and even with his Shadowhunter physical limits, Simon was panting. "Our activity of the past fifteen minutes has taken its toll on poor Lord Montgomery," he announced. "I believe a nap is due."

"Lord Montgomery isn't hungry? Because this fair maiden most certainly is."

Simon groaned. "Izzy, no."

"I'm dead serious." Isabelle sat up in bed, reaching for her bra. The moonlight filtering in through the window shone softly on her white skin, turning it luminescent. Briefly, Simon wished he had back his vampire sight, that he might properly appreciate the way the light of the moon turned her skin to pale crystalline glory. Every day he spent with Isabelle was a day he learned something new about her.

Isabelle had now put on her bra and was pulling on a pair of jeans. Sighing, Simon threw back the covers and reached for a pair of boxers. "What do you feel like eating?" he asked grumpily.

Forty minutes later, the two of them were strolling through the nighttime streets of New York, chewing on pizza slices.

"You know," Simon said through a mouthful of Neapolitan pizza, "maybe this wasn't such a bad idea."

"You should've learned by now that I'm always right," Isabelle responded sweetly. Even with her cheeks full as she munched her greasy pizza, Simon reflected, she managed to look sexy.

It was getting late, and New Yorkers were beginning to go to bed. Simon loved his hometown fiercely – you couldn't have a more New York upbringing than the one he'd had in Brooklyn. He loved everything about the city, everything that everyone else found revolting: the stink of pollution and exhaust, the garbage, the urine, the incessant traffic noises and honking, all this was home to him. New York was part of him just as much as the Angel's blood now was.

"Don't you ever feel like you have the world at your feet in this city?" Simon exclaimed as they discarded their pizza boxes in a nearby garbage can. "Like everything's possible? Like you're in the capital, the centre of the universe?"

Isabelle regarded him thoughtfully with her dark, dark eyes. "Maybe. You grew up a mundane – maybe that's why you feel that way. For me, and for those of us who grew up Nephilim, Alicante is the centre of our world. The city of glass and demon towers will always be the focal point around which our universe revolves."

Simon made a face. "Yeah, Alicante's pretty. But do they do pizza there the way they do here?"

Isabelle laughed. "You'd think they would, since Idris is in Europe, but no, not really…"

They were walking out of Manhattan now, onto Brooklyn Bridge. The dark, swirling waters of the East River churned below them. Once upon a time, Simon and Isabelle might have caught a glimpse of laughing nixies or singing mermaids, playing in the surf. Not anymore. In the years since the Dark War and the Cold Peace that had followed, the water-dwelling faeries of New York had hardly been seen or heard of, retreating into the depths of the water where they couldn't be followed. The Fair Folk as a whole had largely retreated from the mundane world into their own lands, forced into isolation on the fringes of the Shadow World by the Clave. Looking down into the dark water now, Simon had a disturbing thought.

"What if the nixies and mermaids are dead?" he remarked to Isabelle. She snorted and laughed.

"Dead? Why would they be?"

"We haven't heard from them in years. Surely there'd be some evidence of their continued existence if they were alive."

Isabelle sighed in affectionate exasperation, a sigh that told Simon even though he was a Shadowhunter now, he had a long way to go. "When the fey agreed to the Cold Peace, they essentially agreed never to show their faces in polite society again. And they haven't. They're very good at hiding when they need to, faeries. And what they've – "

She broke off abruptly. Simon turned to her in puzzlement, only to find her eyes flashing in alarm. She was looking down at her neck, where her ruby necklace hang. It glinted dully in the weak moonlight. As Simon watched, the ruby pendant pulsed.

Isabelle's head whipped up, the playfulness of her expression gone, her eyes alert and watchful and wary. "Demons," she whispered, even as the stench of a demonic presence hit Simon's nostrils.

Without saying a word, Simon drew a short tube from the inside of his boot. " _Michael_ ," he whispered, and the seraph blade blazed to glorious life. Out of the corner of his eye, he saw Isabelle begin to unwind her electrum whip from her wrist.

"Hero time," Simon whispered as the two Shadowhunters inched forward.


	2. Chapter 2

A nighttime stroll in New York was never just that, was it? Not for Shadowhunters. On this Simon ruefully lamented as he traced a Soundless rune onto his ankle with his stele.

"I told you we should've ordered in," he hissed to Isabelle, who was slinking ahead of him.

Isabelle shot him a glare. "Not now, Simon." Isabelle wasn't a particularly serious girl about anything but her family and Shadowhunting. It was part of growing up Nephilim, Simon supposed.

Seraph blade in hand, Simon followed Isabelle quietly along Brooklyn Bridge. It was late enough that the mundanes who usually frequented the bridge were gone, tucked safely into bed. Simon thanked the Angel that at least there would be no mundane casualties, whatever happened.

Isabelle's ruby pendant pulsed again, and she frowned. "That's odd –," she began, and got no further.

They appeared seemingly out of nowhere, clambering over the railings on either side of the pedestrian walkway of Brooklyn Bridge. Two Shax demons, large and horrible and insect-like. Their pincers, lined with sharp teeth, gnashed hungrily, sending spittle flying. Beady insect eyes on stalks regarded Simon and Isabelle greedily, their elongated, scaly bodies twitching with excitement as they advanced on their six legs. They were hideous arthropods, and reeked of decay and rot.

"Not exactly my idea of a romantic nighttime stroll," Isabelle admitted.

"Isn't it? I've always thought an attack by demon scorpions would be the perfect end to a date," Simon mused.

One of the demons hissed, and then they lunged forward, and Simon and Isabelle flung themselves into battle.

Isabelle, along with other Shadowhunters like Clary, Jace and Alec, had described to Simon the calm that descended upon them when in battle. It wasn't until Simon had Ascended that he'd understood what they meant. Maybe it was that he was now an angelic warrior, but battle provided an inexplicable clarity for Simon now. Even as a Shax demon launched itself at him with snapping pincers, Simon saw what he had to do as if a blueprint had been laid out before him. He sidestepped and lashed out with his seraph blade as the demon surged past him, striking the creature's insect-like carapace. The demon howled, and turned on him. Shax demons weren't the brightest, but this one seemed unusually persistent as, much to Simon's chagrin, it rushed him with its front two legs raised. It was all he could do to duck out of the way this time.

The demon whirled to face him, its eyes glittering with hatred. As it came towards him, it reared up on its hind two legs. Simon saw his chance. With Shadowhunter speed, he fell to the ground and slid under the demon, and, before the creature could come after him, slashed upwards with his seraph blade, piercing its insect armour and running it through.

The demon let out a scream, and then exploded, disappearing as it returned to its home dimension. Simon shielded his face as demon ichor rained down on him, hissing in pain as the demon's blood burned him.

Sitting up, he watched Isabelle in action. She had never looked more beautiful to him. Her pale skin shone dimly in the streetlights on the bridge, her black hair whipping around her like a cloud, her dark eyes glittering, alive with battle. As Simon watched, she brought her silvery-gold whip crashing down upon her demon's back, leaving a slash in its carapace. In fact, Simon noted, there were numerous slashes in the insect's armour.

Simon watched, entranced, as Isabelle continued her deadly dance around the demon. Where the demon lunged, rough and aggressive, Isabelle spun gracefully out of its way as if it were nothing, a move in ballet class. Her whip came down again and again, raining pain and injury on the beast before her.

Until the beast raised a foreleg as the whip came down, caught the whip and used it to yank her towards it.

Isabelle's feet went out from under her and she crashed to the ground. She skidded, pulled by the demon holding her whip, closer to the gnashing pincers.

Simon let out an involuntary sound. He got to his feet and charged towards them, but even with the speed of the Nephilim he was too slow, he'd never get there in time –

He shouldn't have underestimated Isabelle Lightwood.

Even as she was pulled unwillingly towards the hungry demon, Isabelle slipped her free hand into one of her boots and extracted a knife, a runed blade that Simon had seen her use in practice at the Institute. She hauled it back and then thrust it forward, stabbing it right into the centre of the demon's pincers.

The demon let out a gurgling noise and stilled. Isabelle yanked her whip back from the demon and with a wave, wrapped it round its short, stubby neck. Then with a grunt and a pull, the whip came free, shearing the demon's head off with it.

The Shax demon vanished, sucked away to another dimension, and Isabelle got to her feet, a disgusted expression on her face. It was only then she noticed Simon standing there, staring at her. "What?" she demanded.

Simon closed the space between them in two steps and kissed her. He felt her tense, surprised, under his lips, but gradually she relaxed, leaning into him and responding. He took her in his arms and lifted her off bodily the ground despite her muffled, half-serious protests. His eyes were closed, his mind full of nothing but Isabelle, always Isabelle with the dark eyes.

It was a few minutes before he set her down and detached herself from her. She looked at him, an expression of mock indignation on her face. "You wanna tell me what that was?" she demanded.

"I – I thought that thing had you," Simon said breathlessly. "When it pulled you towards it…"

Isabelle rolled her eyes. "What have we said before about underestimating me, Simon? Never do it. Ever. It'll just end badly for you."

"I know," Simon said, "and I promise I'll never do it again."

"What are you talking –" Isabelle began, then broke off, her eyes widening, as Simon encircled her with his arms again, pulling her up against his chest.

"Marry me, Isabelle Lightwood," he said, his voice rough with relief. "Marry me."

Isabelle's mouth dropped open in shock. "Simon!"

Simon was as surprised as she was – or he thought he was. But the longer he thought about it, the more he realized that wasn't the case. He had never loved anything so fiercely, so unconditionally as he loved the girl standing before him. When first he'd met her, he'd thought she was a cold creature, as cold as the Shadowhunter race to which she belonged, cold like a star – distant and unattainable. But things had changed since then, and he had come to realize what he in fact should have always known: Isabelle's was the warmest of hearts, the most caring of human beings, the only one he could imagine who could have fallen in love with first a vampire, then a mundane, and now a Shadowhunter, the only girl he knew who could have captured his heart not once, but twice. Falling in love with Isabelle hadn't been instantaneous, like a supernova, the way Clary and Jace had fallen in love – it had been slow, steady, hard-earned and hard-won, and all the more rewarding and more beautiful for it. And the way she was looking at him now, Simon realized that not only was he the only man to whom she'd ever entrusted her heart, he was the only man who'd ever rendered her speechless.

"Izzy?" he prompted.

"Yes!" Happiness burst from Isabelle's eyes like a fountain. "Oh, Simon, yes!"

Her lips crashed against Simon's, and he responded, lifting her off the ground again. He tasted salt on her lips and realized it was tears, and that she was crying, and belatedly that he was too. He loved her all the more for it, and deepened his kiss.

It was a Shadowhunter's proposal – not necessarily the most romantic, with the two of them drenched in demon ichor. But neither of them would have traded it for the world.


End file.
